<template>
  <view>
    <view class="scroll-view-container">
      <!-- 左侧滑动区域 -->
      <scroll-view scroll-y="true" :style="{height: wh +'px'}" class="left-scroll-view">
        <block v-for="(item,i) in cateList" :key="i">
          <view  :class="['left-scroll-view-item',i===active?'active':'']" @click="activeChanged(i)">
            {{item.cat_name}}
          </view>
        </block>
      </scroll-view>
      <!-- 右侧滑动区域 -->
      <scroll-view scroll-y="true" :style="{height: wh +'px'}" :scroll-top="scrollTop">
       <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
          <!--二级分类标题  -->
         <view class="cate-lv2-title">
           / {{item2.cat_name}} /
         </view>
         <!-- 三级分类 -->
         <view class="cate-lv3-list">
           <!-- 三级分类的item项 -->
           <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
             <!-- 三级分类的图片 -->
             <image :src="item3.cat_icon.replace('ugo-dev','hmugo-web')"></image>
             <!-- 三级分类的文本 -->
             <text>{{item3.cat_name}}</text>
           </view>

         </view>
         
         
       </view>
        
      </scroll-view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        // 当前设备可用的高度
        wh: 0,
        cateList:[],
        active:0,
        cateLevel2: [],
        scrollTop: 0
      };
    },
    onLoad() {
      // 微信自己的api，获取屏幕高度宽度等
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight
      
      this.getCateList()
    },
    methods: {
      async getCateList(){
        const {data: res} = await uni.$http.get('/api/public/v1/categories')
        if(res.meta.status !== 200) return uni.$showMsg()
        
        this.cateList = res.message
        
        // 默认：为二级分类赋值
        this.cateLevel2 = res.message[0].children
        
      },
      activeChanged(i){
        this.active = i
        //重新为二级分类赋值
        this.cateLevel2 = this.cateList[i].children
        
        this.scrollTop = this.scrollTop === 0?1:0
        
      },
      //跳转到商品列表页面
      gotoGoodsList(item){
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item.cat_id
        })
      }
      
    }
  }
</script>

<style lang="scss">
  .scroll-view-container {
    display: flex;
  }
  .left-scroll-view {
    width: 120px;
    .left-scroll-view-item {
      background-color: #F7F7F7;
      line-height: 60px;
      text-align: center;
      font-size: 12px;
      &.active {
        background-color: #FFFFFF;
        position: relative;
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #C00000;
          position: absolute;
          top: 50%;
          left: 0;
          transform: translateY(-50%);
        }
        
      }
    } 
  }
  .cate-lv2-title {
    font-size: 12px;
    font-weight: bold;
    text-align: center;
    padding: 15px 0;
  }
  .cate-lv3-list {
    display: flex;
    flex-wrap: wrap;
    
    .cate-lv3-item{
      width: 33.33%;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      margin-bottom: 10px;
      
      image {
        width: 60px;
        height: 60px;
      }
      
      text {
        font-size: 12px;
      }
    }
  }

</style>
